Singapore were eliminated at the group stage of the 2018 AFF Suzuki Cup on Sunday, but while many saw their performances as a step forward former coach Bernd Stange has told ESPN FC that the country has to make big changes if it is to progress.

The German spent three years in charge of the national team from 2013 but was not happy with what he saw from them in Southeast Asia's biennial competition, especially in the 3-0 loss to Thailand on Sunday that sealed a first-round exit.

"Nothing has changed in Singapore," Stange told ESPN FC from Damascus where he is preparing Syria for the 2019 Asian Cup in January. "The gap with Thailand is bigger than ever before; they were outclassed."

Stange left Southeast Asia in April 2016 and was succeeded by V. Sundramoorthy who was criticised for his defensive tactics during a dismal 2016 AFF Suzuki Cup campaign.

Under Fandi Ahmad, appointed on a temporary basis in May, Singapore have adopted a more attacking style. But while fans have called for the appointment to be made permanent, according to Stange, it will not make much difference.

"In the last few years, they have moved backwards," he said. "Under V. Sundramoorthy, they played a style of football of "park the bus" that was not the way for young players. Fandi was my assistant and he wants fast-passing football. He tried make the change but there is no chance for success."

Stange, 70, believes that there has to be a fundamental change off the pitch for Singapore to improve on it.

"Until the government and the sporting authorities show a genuine desire to make football more professional and to make changes, then it will stay the same," he added. One of the major changes, he says, has to come in the Singapore Premier League where foreign teams such as Albirex Niigata of Japan and Brunei's DPMM have won the last four league titles between them.

"There has to be a league without foreign teams, a small league with just eight [Singapore based] clubs," Stange said. "These clubs must then have a professional base, youth teams at under-21, U19 and U16 levels and this is just a first step. At the moment, there is a league that is not loved and it not watched by fans.

"Singapore can make amazing buildings but can't provide good pitches for its teams. I am sorry for fans who love football but this has to change."